Potassium Phosphate, Tribasic → HCID 58042453, compound

Participants

Reaction Conditions

Reaction Steps

2-Bromo-3-(1,1-difluoroethoxy)pyridine (Preparation 266, 700 mg, 2.948 mmol), cycloproyl boronic acid (252 mg, 2.94 mmol), and potassium phosphate tribasic (1.56 g, 7.35 mmol) were suspended in a mixture of toluene (100 mL) and water (20 mL), with rapid stirring. The suspension was heated to 80° C., and the solvent de-gassed by direct bubbling of N2 gas through the suspension for 30 minutes. The reaction was then heated to 95° C., and tricyclohexyl phosphine (82 mg, 0.29 mmol), rapidly followed by palladium acetate (33 mg, 0.15 mmol), were added. The reaction was left to stir and heat at 95° C. for 18 hours. The reaction was cooled to room temperature, and filtered through a plug of arbocel, eluting with ethyl acetate. The solvent was removed to leave a dark yellow oil. Ethyl acetate was added (100 mL), and the organic phase extracted with 2M HCl solution (3×100 mL). The organic phase was discarded. Ethyl acetate (150 mL) was added to the combined aqueous layers, and solid sodium bicarbonate was added until the aqueous layer reached pH 7. The mixture was transferred to a separating funnel, the organic layer was removed and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic phases were dried over magnesium sulfate, filtered and the solvent removed to leave a yellow oil. The material was purified by silica gel column chromatography eluting with 1:1 heptane:ethyl acetate to afford the title compound as a colourless oil (252 mg, 43%).

Provenance & Evidence